1. Field of the Invention
The present invention relates to a winding configuration for yarn on a bobbin for use in a weaving operation to reduce bobbin pay-out failures due to yarn-on-yarn abrasion and reduce handling.
2. Technical Considerations
Glass fibers are commonly formed by attenuating molten glass through orifices in a bushing. The fibers are then drawn across an applicator which coats at least a portion of the fiber surface with a sizing composition, gathered into one or more discrete strands by gathering shoes, and wound on a winding machine into a forming package. The forming packages are then collected and typically placed in a drier to dry the sizing composition. After drying, the forming packages are moved to a twist frame where the fiber strands are unwound from the forming package and wound onto a bobbin. The bobbins are thereafter used to form warp beams and supply weft, or fill, yarn during a weaving operation.
In a typical glass fiber yarn weaving operation, the warp yarn is supplied by a loom beam which includes from several hundred to several thousand glass fiber strands. To form the loom beam, bobbins having the warp yarn are positioned in a creel and the yarn strands are threaded through guides and wound around a section beam. Several section beams, typically 2 to 8 section beams, are then combined, e.g. by a rebeaming or slashing operation, to form a loom beam. Traditionally, the glass fiber warp yarn is wound on the bobbins in a xe2x80x9cpirnxe2x80x9d or xe2x80x9cbottlexe2x80x9d shape or build. In a pirn build, the wound package on the bobbin includes a generally cylindrically shaped central portion and tapered end portions. In a bottle build, the wound package on the bobbin includes a generally cylindrically shaped lower portion and a tapered upper portion. Both of these builds are formed by traversing the twist ring rail of a twist frame over all parts of the bobbin in a cycle that is completed approximately every twenty minutes and repeated until the bobbin is filled, i.e. until the desired bobbin weight is achieved.
As the warp yarn is removed from the bobbin (sometimes referred to herein as xe2x80x9cpay-outxe2x80x9d) to form the loom beam, the yarn can be dragged along the underlying layer of yarn. This yarn-on-yarn abrasion can cause broken filaments and yarn breakage
It would be advantageous to provide a yarn package on a bobbin that reduces this breakage and accompanying broken filament and yarn while maximizing the amount of yarn on the bobbin.
The present invention provides a method of forming a wound fiber package, comprising: winding a first portion of strand comprising at least one fiber on a bobbin using a first indexing ratio A:B, wherein A is greater than 0 and A is greater than B; and winding a second portion of strand comprising at least one fiber on the bobbin using a second indexing ratio A:B different from the first indexing ratio, wherein A and B are greater than 0. In one non-limiting embodiment of the invention, B equals 0 in the first indexing ratio, A in the first indexing ratio equals A in the second indexing ratio and A equals B in the second indexing ratio. In another non-limiting embodiment of the invention, B is greater than 0 in the first indexing ratio, A in the first indexing ratio equals A in the second indexing ratio and A equals B in the second indexing ratio.
The present invention also provides a method of forming a wound fiber package, comprising: forming an initial section of strands comprising at least one fiber, the initial section having a conical shaped surface and a desired package diameter; and winding a plurality of successive strand layers over the conical shaped surface while maintaining the desired package diameter so as to form a wound fiber package comprising a cylindrical portion and a conical shaped portion at one end of the cylindrical portion.
The present invention further provides a method of forming a wound glass fiber package, comprising: winding a strand comprising at least one glass fiber on a bobbin using an indexing ratio A:B, wherein A is greater than 0, so as to form a wound package comprising at least a conical shaped portion.
Another aspect of the present invention is a wound fiber package, comprising: a first portion of strand comprising at least one fiber on a bobbin having a first indexing ratio A:B, wherein A is greater than 0 and A is greater than B; and a second portion of strand comprising at least one fiber on the bobbin having a second indexing ratio A:B different from the first indexing ratio, wherein A and B are greater than 0. In one non-limiting embodiment of the invention, B equals in the first indexing ratio, B equals 0, A in the first indexing ratio equals A in the second indexing ratio and A equals B in the second indexing ratio. In another non-limiting embodiment of the invention, B is greater than 0 in the first indexing ratio, A in the first indexing ratio equals A in the second indexing ratio and A equals B in the second indexing ratio.
The present invention also provides a wound fiber package comprising at least one strand comprising at least one fiber, comprising: a conical section of strand having a conical shaped surface; and a plurality of conical shaped successive layers of strand overlaying the conical surface of the conical section, wherein the successive layers form a package having; a generally cylindrical shaped portion; and a conical shaped portion at one end of the cylindrical portion.
The present further provides a wound fiber package comprising at least one strand comprising at least one fiber, comprising: a plurality of overlaying conical shaped strand layers forming a generally cylindrical shaped portion and a conical shaped portion comprising an inclined conical surface at one end of the cylindrical portion.
Another aspect of the present invention is a wound glass fiber package, comprising: a plurality of conical shaped overlaying layers of strand comprising at least one glass fiber, forming a conical shaped portion having an indexing ratio A:B, wherein A is greater than 0.